<template>
   <div class="todo-footer">
        <label>
          <input type="checkbox" v-model="isCheckAll"/>
        </label>
        <span>
          <span>已完成{{overNum}}</span> / 全部{{totalNum}}
        </span>
        <button class="btn btn-danger" @click="deleteAllCheck">清除已完成任务</button>
      </div>
</template>
<script>
export default {
  name: 'Footer',
  props:["todoList","changeAllTodo","deleteAllCheckTodo"],
  data() {
    return {
      
    };
  },
  methods:{
    deleteAllCheck(){
      this.deleteAllCheckTodo()
    }
  },
  computed:{
    totalNum(){
      return this.todoList.length
    },
  overNum(){
    return this.todoList.reduce((prev,item) => {
      if(item.isOver){
        prev += 1
      }
      return prev
    },0)
  },
  isCheckAll:{
    get(){
      return this.todoList.every(item => item.isOver) && this.todoList.length
    },
    set(val){
      this.changeAllTodo(val)
    }
  }
  }
}
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}

</style>
